We will continue to develop and use the techniques of cyclic nucleotide immunocytochemistry for the localization of cGMP and cAMP in tissues and in cells grown in culture. We will attempt to quantitate this methodology. We will continue to utilize cyclic nucleotide dependent protein kinase immunocytochemistry and develop radioimmunoassays for these proteins. We will begin to utilize antisera to the calcium-dependent regulator and to the heat labile modulator binding protein in immunocytochemical studies. Specific areas of emphasis include the role of cyclic nucleotides and calcium in the regulation of cell motion and muscle contraction, in the action of hormones such as glucagon in liver, in hormone secretion, in phagocytosis, and in the control of transport in human and canine erythrocytes.